I do think the position of national manager should be no different to that of club manager when a person is plying their trade to be a manager which is starting off at lower division teams to learn the job and get much needed experience and then move up through the divisions. The same should be applied to national managers, once a manager has become very experienced at club management, find a low ranked country that could benefit from an experience club manager, learn the differences to club management and national management and then move up through the ranks to the top national teams. Some managers are better than others who would not need to do that.
I looked through the list of men's world cup winners, who their manager was, their nationality and how long it took them from starting as national manager to winning the world cup. The managers nationality is in brackets
2022 - Argentina - Lionel Scaloni (Argentina) 4 years
2018 - France - Didier Deschamps (France) 6 years
2014 - Germany - Joachim Low (Germany) 8 years
2010 - Spain - Vincente del Bosque (Spain) 2 years
2006 - Italy - Marrcello Lippi (Italy) 2 years
2002 - Brazil - Luiz Felipe Scolari (Brazil) 1 year
1998 - France - Aime Jacquet (France) 5 years
1994 - Brazil - Carlos Alberto Parreira (Brazil) 3 years
1990 - West Germany - Franz Beckenbauer (Germany) 6 years
With the exception of Joachim Low you can see that since 1990, it takes up to 6 years for a national manager to win the world cup. Gareth Southgate had been in charge of the England squad for 8 years and never won the world cup. You will also note from that list that no foreign manager has won the world cup, it has always been won by one of their own countrymen. You can see why England fans want an English manager because history is not on their side for wanting a foreign manager.